Note: Descriptions are shown in the official language in which they were submitted.
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F OLDABLE STEPLADDER
The present invention relates to a foldable stepladder.
Foldable stepladders are known whieh are constituted by:
- a first pair of two main, generally parallel, uprights;
- a plurality of rungs, each comprising two parts articulated,
on the one hand, one on one of the main uprights9 the other on the
other main upright, on the other hand, on each other and on a central
upright which is generally parallel to the main uprights and to said
parts of each rung;
- a device for maintaining said rungs in their unfolded confi-
guration;
- a second pair of two auxiliary uprights associated with
said main ~Iprights to maintain said main uprights and said rungs
in their position of use;
- compasses having two legs articulated on each other and
each articulated on one of the auxiliary uprights in order to maintain
these auxiliary uprights in spaced apart relationship when the step-
ladder Is in use.
However, such foldable stepladders comprise relatively
complicated means for placing them in position of use and in folded
up position and it i5 particularly difficult to manoeuvre them.
Furthermore, stability of these stepladders is not always
absolutely perfect.
It is an object of the present invention to overcome these
drawbacks.
According to the invention, the auxiliary uprights are articu-
lated at one of their ends on the upper part of the main uprights
and they are articulated on each other about a shaft in their median
part to present, in unfolded position of use, the form of a cross,
said auxiliary uprights being connected from said mutual point of
articulation to the central upright by a connecting rod.
With the device according to the invention, opening of
the stepladder is total and simultaneous upon opening of the auxiliary
uprights by moving the main uprights away.
Stability is excellent, the rear auxiliary uprights forming
a three-sided triangulation with the~spacer rod.
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As the stepladder does not require any Jocking, opening
and closure thereof may be effected in one manoeuv~e.
The invention will be more readily understood on reading
the following description with re~erence to the accompanying drawings,
5 in which:
Fig. I is a view of the stepladder in side elevation and in
folded position.
Fig. 2 is a view of the stepladder in rear elevation and
in unfolded position for use thereof.
Fig. 3 is a plan view showing the removable upper crosspiece.
Fig. 4 is a view in elevation on a larger scale showing the
rneans for articulation of the uprights.
Fig. S is a view in section along line V-V of Fig. 4.
Referring now to the drawings, Figs. 1, 2, 4 and 5 show
15 a stepladder according to the invention which comprises two main
uprights I and 2, a central upright 3 and steps in two parts 4 and
5 which are each mounted to pivot, on the one hand, on the main
uprights about pins 6, 7, respectively perpendicular to the plane
of the main uprights 1, 2 and in fact generally horizontal, on the
20 other hand, on the central upright about pins 8, parallel to said pins
- 6 and 7.
The steps 4, 5 present in transverse section a trapezoidal
form with a flat part for support.
In the lower part of the main uprights are articulated about
25 pins 9, 10, the two legs 11 and 12 of compasses, which legs are articu-
lated on each other about a pin 13, said legs, whose length is greater
than parts 4 and 5 of the steps, forming an angle of which the apex
is directed upwardly to engage in a corresponding housing provided
- at the base of the central upright 3 when the stepladder is in unfolded
30 position (Fig. 2).
In the upper part of the main uprights 1, 2 are articulated,
at one of their ends, auxiliary uprights 14, 15 which rest on the ground
by their other end 16, 17, said auxiliary uprights being articulated on
each other in their median par~ about a pin 18 to present in unfolded
35 position for use (Fig. 2) the form of a cross. The auxiliary uprights
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14, 15 are connected from the pivot pin 18 by a small rod 19 to the
central upright 3. To this end, one of the ends of the connecting
rod 19 is articulated about a pin 20 mounted on a fork joint 21 itself
articulated on the pin 18 for connection of the auxiliary uprights
14, 15; at its other end the rod 19 is articulated on a pin 23 engaged
on the central upright 3.
The articulation of auxiliary uprights 14, 15 (Figs. 4, 5)
on the upper part of the main uprights 1, 2 is effected by means
of hinges 24, 25. Each hinge such as 24 comprises a pin 26 and two
arms 27, 28 which are articulated respectively about a pin 29 on
the main upright 1, 2 and about a pin 30 on the auxiliary upright
14, 15.
Pin 26 of hinge 24, 25 is perpendicular to pins 29 and 30
for articulation on the main upright 1, 2 and on the auxiliary upright
14, 15.
In the upper part of the main upright 1, there is articulated
about a pin 31 a crosspiece 32 (Figs. 1, 2, 3) constituted by a U-shaped
section of which the other end is removably fixed on the upright
2 by means of a pin 33 connected to said upright by a chain 34.
The crosspiece 32 constitutes a groove adapted to support small
objects and it reinforces rigidity of the stepladder.
The device according to the invention operates as follows:
When the stepladder is in folded position as shown in Fig.
1, it suffices to move the main uprights 1, 2 laterally apart from ~
each other so that the two parts 4, 5 of the steps occupy a horizontal
position for use and the two legs of the compasses 11, 12 come into
abutment by their vertex against the central upright 3.
During displacement of uprights 1, 2, the auxiliary uprights
14, 15 are moved away from each other, pivoting about their central
axis 18 and the connecting rod 19 is moved, pivoting about axes 20
and 23 to occupy the position shown in Fig. 2.
The spacer rod 19 with the auxiliary uprights 14, 15 form
a three-sided triangulation which ensures excellent stability of the
stepladder.
The crosspiece 32 is then mounted and held by its pin 33.
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The invention is, of course, not limiting and the man skilled
in the art may make modifications thereto withou~ departin~ from
the domain of the invention; in particular, hinges 24, 25 may be
replaced by ball-and-socket joints.
